Pelvic anatomy for colorectal surgeons

Area of Science:

• Surgical Anatomy
• Embryology
• Colorectal Surgery

Background:

• Recent advances in rectal surgery emphasize total mesorectal excision (TME) and autonomic pelvic nerve preservation.
• Effective TME necessitates a thorough understanding of rectal embryology, pelvic floor anatomy, and lymphatic drainage patterns.

Purpose of the Study:

• To review the embryological development of the rectum and anal canal.
• To elucidate the complex anatomy of the pelvic floor and mesorectum.
• To detail the distribution of lymphatic nodes and the course of autonomic pelvic nerves relevant to TME.

Main Methods:

• Review of embryological development of the hindgut, rectum, and anal canal.
• Detailed anatomical description of the mesorectum, pelvic fascia, and autonomic pelvic nerves.
• Explanation of the surgical plane ('holy plane') for TME and nerve preservation.

Main Results:

• The mesorectum harbors critical blood vessels and lymphatic nodes.
• The 'holy plane' is defined between the perirectal and pelvic fascia, crucial for TME.
• Adherence to this plane maximizes the chances of preserving autonomic pelvic nerves, including the hypogastric plexuses and nerves.

Conclusions:

• A comprehensive understanding of rectal embryology and pelvic anatomy is essential for colorectal surgeons.
• Precise identification and dissection along the 'holy plane' are key to successful TME with autonomic nerve preservation.
• These anatomical insights are critical for improving surgical outcomes and functional recovery in rectal cancer surgery.